actually, the spark plug wires were routed the way they are by the previous owner. you can install plug wires in a better manner than what you see in the picture even with headers. but as you note, you have to be careful to keep plug wires away from the header tubes which get extremely hot - like red hot hot. it is a much better idea to wrap header tubes with heat wrap which i intend to do once i get to that step which at this point, is pretty FAR off!